Author Interviews, Erectile Dysfunction, JAMA, Karolinski Institute / 23.03.2020 Interview with: Alexander Stridh, MSc Department of Clinical Neuroscience Karolinska Institute Solna, Sweden What is the background for this study? What are the main findings? Response: ​We wanted to investigate how large the effect size is in the placebo arm of clinical trials with PDE5Is for erectile dysfunction. The major findings in this study is that there is a placebo response in general in ED, though it is hard to tell if this is a genuine placebo effect rather than normal fluctuations in symptom severity among patients. Another interesting finding was that the placebo response seems largely more important when the cause of ED is mainly due to psychogenic factors, as in post traumatic stress disorder. Lastly there was an important finding that there was no difference between placebo and active drug with daily treatment of PDE5Is  for long term recovery of erectile function after prostate cancer treatment, a practice which is common in some places and seems to be questionable.  (more…)
Author Interviews, Brain Injury, Erectile Dysfunction, JAMA / 26.08.2019 Interview with: Rachel Grashow PhD Research Associate Department of Environmental Health Football Players Health Study at Harvard University Harvard T.H. Chan What is the background for this study? Response: It has been previously shown in small studies of boxers and military personnel that traumatic brain injuries can damage the pituitary gland, which serves as the "master controller" of hormone function in the brain. These studies on individuals at risk for repeated head injury found that hits on the head caused deficiencies in certain hormones, such as growth hormone and testosterone, which could have downstream effects on sexual function. Only one large study was conducted that used Taiwanese health insurance data and looked at single traumatic brain injuries and risk of erectile function (ED). In that study, men who experienced a single severe TBI were more than twice as like to report ED after their injury. In light of these findings, important questions remain regarding whether multiple head injuries are associated with pituitary or sexual dysfunction in a large population with other ED-related health issues. The Football Players Health Study at Harvard University asked former NFL players to fill out a questionnaire that interrogated demographic factors, football-related exposures and current health conditions. Specifically, we asked participants to self-report the frequency of ten different concussion symptoms experienced during professional play, as well as whether a clinician had ever recommended or prescribed medication for low testosterone or ED.   (more…)
Author Interviews, Erectile Dysfunction, Heart Disease / 20.03.2019 Interview with: Jagat Narula, MD, PhD Philip J. and Harriet L. Goodhart Professor of Medicine (Cardiology) Associate Dean for Global Health Director of the Cardiovascular Imaging Program Mount Sinai Medical Center What is the background for this study? What are the main findings? Response: Atherosclerosis has been linked to causing erectile dysfunction (ED) in the majority of patients with this cardiovascular condition, but researchers have not had the means of demonstrating atherosclerosis in penile arteries until now.  This unique study uses advanced imaging to detect how strong the association actually is.  For the first time, researchers have used advanced imaging of penile arteries to show a link between atherosclerosis and erectile dysfunction (ED). (more…)
Author Interviews, Cancer Research, Chemotherapy, Erectile Dysfunction / 18.04.2018 Interview with: Dr Pan Pantziarka, PhD Program Director, Drug Repurposing: Anticancer Fund Coordinator: Repurposing Drugs in Oncology ( What is the background for this study? What are the main findings? Response: The Repurposing Drugs in Oncology (ReDO) project is an on-going collaboration assessing the evidence of anticancer activity in a wide range of already licensed non-cancer drugs. A subset of these drugs have a sufficient level of evidence to support clinical investigation and these are profiled in detail in order to synthesise the existing evidence and to bring it to the attention of clinical researchers. In the case of the PDE5 inhibitors sildenafil, tadalafil and vardenafil the evidence is clear that these drugs have multiple anticancer mechanisms of action at clinically relevant dosing. In particular there is evidence that these drugs target anti-tumour immune responses, as shown from a small number of early stage clinical trials. This opens up the prospect of using these cheap and widely available drugs in combination with existing therapies to improve the number and duration of responses. The chance to increase the therapeutic effectiveness of immune checkpoint inhibitors is especially compelling and definitely warrants clinical research. (more…)
Author Interviews, Diabetes, Erectile Dysfunction / 21.07.2017 Interview with: Damiano Pizzol  Operational Research Unit, Doctors with Africa Cuamm Beira, Mozambique What is the background for this study? Response: Since the 1970s the association between diabetes and the development of erectile dysfunction has been documented both in animal models and humans Several studies have considered the prevalence of erectile dysfunction in diabetes and the majority agree that the incidence of erectile dysfunction in men with diabetes is two- to three-fold higher than in the general population. It is estimated that erectile dysfunction affects up to 75% of all men with diabetes, it is age correlated and occurs at a younger age in men with diabetes. (more…)
Author Interviews, Erectile Dysfunction, Gout / 27.11.2016 Interview with: Dr Edward Roddy Clinical Senior Lecturer in Rheumatology and Honorary Consultant Rheumatologist Arthritis Research UK Primary Care Centre Research Institute for Primary Care & Health Sciences Keele University Staffordshire UK What is the background for this study? What are the main findings? Response: Both gout and erectile dysfunction (ED) are prevalent in the general population, and share some common risk factors such as obesity, alcohol consumption and comorbidity (vascular disease, renal disease etc). We undertook a retrospective cohort study in UK Clinical Practice Research Database, a large longitudinal UK database of UK computerised primary care records, to quantify the risk of incident ED in men with gout. We found that men with gout had 30% greater risk of developing erectile dysfunction than men without gout, after adjusting for confounding variables such as lifestyle factors and comorbidity, although the absolute increased risk was small (0.6%). We did a further analyses including men who already had ED when they were diagnosed with gout, finding that they were also at increased risk of being diagnosed with ED in the year before they developed gout, suggesting that hyperuricaemia, which people can have for decades before developing gout, may be a key reason to explain the increased risk of erectile dysfunction in people with gout. Apparently, some people who make use of content on websites similar to to aid in alleviating their ED. (more…)
Author Interviews, Erectile Dysfunction, Prostate Cancer, Urology / 05.08.2016 Interview with: Juzar Jamnagerwalla, MD Division of Urology, Department of Surgery Cedars-Sinai Medical Center Los Angeles, California What is the background for this study? What are the main findings? Response: In mouse models phosphodiesterase type-5 inhibitors (PDE-5i) have been shown to have anti-neoplastic activity, and given the routine use of PDE-5i for treatment of erectile dysfunction after prostatectomy several studies have examined the association between PDE-5i use and biochemical recurrence after treatment for prostate cancer with mixed findings. Only one previous study has explored the association between risk of prostate cancer, finding that men on PDE-5i had a lower chance of being diagnosed with prostate cancer. Given this, we tested the relationship between PDE-5i use and risk of prostate cancer in 6,501 men in the REDUCE study finding that PDE-5i use was not associated with prostate cancer diagnosis. On secondary analysis, among North American men who had a much higher baseline use of PDE-5i use, there was an inverse association between PDE-5i use and prostate cancer diagnosis, which approached, but did not reach statistical significance. (more…)
Author Interviews, Erectile Dysfunction, Melanoma, PLoS / 16.06.2016 Interview with: Anthony Matthews Department of Non-Communicable Disease Epidemiology, London School of Hygiene & Tropical Medicine London, United Kingdom What is the background for this study? Dr. Mathews: :The drug Viagra, which is used to treat erectile dysfunction, is one of a class of drugs called PDE5 inhibitors. Laboratory studies of cells from the skin cancer, malignant melanoma, suggest that PDE5 inhibitors might promote their growth, so there have been some concerns that people using these drugs might have an increased risk of malignant melanoma. Two previous studies comparing melanoma rates in PDE5 inhibitor users and non-users came to differing conclusions so we wanted to look further into this. To carry out the study we used anonymised GP records from the UK identifying over 150,000 men with a PDE5 inhibitor prescription, and over 500,000 men of a similar age, and from the same areas, who didn’t have a PDE5 inhibitor prescription. We then looked for later diagnoses of malignant melanoma to see how people’s exposure to PDE5 inhibitors affected their future risk of being diagnosed with melanoma. (more…)
Author Interviews, Erectile Dysfunction, Stem Cells, Urology / 03.04.2016 Interview with: Dr. Michael Zahalsky MD Medical Director of Urological Oncology North Broward Medical Center, Florida What is the background for this study? What are the main findings? Dr. Zahalsky: Erectile dysfunction or the inability to maintain an erection satisfactory for sexual intercourse is a disease that affects hundreds of millions of men worldwide. Currently, the most utilized methods to help treat these men include oral medications, injectable medications and penile prostheses. We sought out new alternatives to treat and potentially even cure erectile dysfunction by using stem cells and biologic-based therapies - treatments that are now being used in various fields of medicine from orthopedics to plastic surgery. We decided to see how their effect will influence Erectile Dysfunction by evaluating blood flow to the penis. In the past we studied Peyronie’s Disease using a similar treatment modality and showed that with a single injection blood flow improved, plaque size decreased, and penile curvature lessened.  There have been many animal studies, as well, showing the benefit of biologic-based therapies in the treatment of Erectile Dysfunction and Peyronie’s Disease. We chose to use placental matrix derived mesenchymal stem cells in this study on Erectile Dysfunction. We had a small sample of 8 patients who underwent treatment. We had statistically significant increase in blood flow into the penis.  This was demonstrated by an increase in peak systolic velocity using color doppler on ultrasound. (more…)
Author Interviews, Erectile Dysfunction, Prostate, Prostate Cancer, Surgical Research, Urology / 29.02.2016 Interview with: Dr. Pedro Recabal, MD and Memorial Sloan Kettering Cancer Center Department of Surgery, Urology Service New York, NY Urology service, Fundacion Arturo Lopez Perez, Santiago, Chile Dr. Vincent P. Laudone, Memorial Sloan Kettering Cancer Center Department of Surgery Urology Service New York, NY What is the background for this study? Response:  One of the most concerning adverse events that may arise following surgery for prostate cancer (radical prostatectomy) is postoperative erectile dysfunction. The loss of erectile function after surgery is most frequently caused by intraoperative injury to the neurovascular bundles, tiny packages of blood vessels and nerves that conduct the impulses responsible for erection. It is known that if both bundles are removed, patients seldom recover erectile function. Accordingly, neurovascular bundle preservation during Radical prostatectomy has proven benefits in terms of erectile function recovery. However, as these bundles are intimately associated with the posterolateral aspects of the prostate, they must be carefully separated from the surface of the prostate without cutting them, applying excessive traction, or using cautery, all of which could produce irreversible damage and the consequent loss of function. During this dissection, the surgeon risks cutting into the prostatic capsule , which could result in leaving tumor behind. In some cases, the tumor extends beyond the prostate into the neurovascular bundles, and an attempt to preserve these structures could also result in incomplete tumor removal, defeating the purpose of radical prostatectomy. Therefore, many urologists treating patients with “aggressive” tumors (such as the patients in our cohort) would try to avoid leaving cancer behind by removing not only the prostate but also the tissue around it, including the neurovascular bundles. In other words, if you had to chose between removing all the cancer but loosing erectile function, or preserving erectile function but risking an incomplete cancer removal, most patients and surgeons naturally lean towards the first option. Also, in many centers, patients with aggressive prostate cancers are managed with combined treatments (multimodal therapy), by adding hormonal therapy and/or radiotherapy, which could also result in erectile dysfunction. As such, many surgeons believe that there is no rationale for attempting to preserve the neurovascular bundles in these “high-risk” patients because most will end up with erectile dysfunction . However, with the advent of MRI (and integrating other clinical information such as location of the positive biopsies, and intraoperative cues), surgeons can now have a better idea of where the cancer is located, which may aid in surgical planning. For instance, if a tumor is located in the anterior prostate, removing the neurovascular bundles (located on the posterolateral aspects) would provide no oncologic benefit, regardless of the aggressiveness of the tumor. Similarly, if the tumor compromises only the left side, removing the right neurovascular bundle is unlikely to help the patient, but can instead result in harm. Moreover, neurovascular bundle preservation is not an all-or-none procedure; on each side, these bundles can be completely preserved (meaning dissecting exactly along the border between the prostate and the bundle); partially preserved (meaning preserving some of the nerves that are further away from the prostate, and removing the ones that are closer to the prostate); or completely removed along with the prostate (This has been graded in a scale from 1 to 4, where 1 represents complete preservation, and 4 represents complete removal of the neurovascular bundle, with 2 and 3 being partial preservation. This grade is recorded by the surgeon for each side, at the end of the procedure.) As such, sometimes it’s possible to preserve part of the bundle, even if there is a tumor on the same side We designed a retrospective study to look at how high volume surgeons at MSKCC performed radical prostatectomy in high risk patients (how frequently and to what extent where the neurovascular bundles preserved), and what were the outcomes in terms of positive surgical margins (a surrogate for “leaving tumor behind”); use of additional oncologic treatments such as hormone therapy or radiotherapy, and finally, erectile function recovery in patients with functional erections before the operation. The patients in our cohort had at least one NCCN-defined high risk criteria (Gleason score ≥ 8; PSA ≥ 20 ng/ml; Clinical stage ≥ T3). (more…)
Author Interviews, Erectile Dysfunction, JAMA, Melanoma, NYU, Pharmacology / 24.06.2015

Dr. Stacy Loeb, MD, MScDepartment of Urology, Population Health, and Laura and Isaac Perlmutter Cancer CenterNew York University, New York Interview with: Dr. Stacy Loeb, MD, MSc Department of Urology, Population Health, and Laura and Isaac Perlmutter Cancer Center New York University, New York Medical Research: What is the background for this study? Dr. Loeb: A paper published last year suggested a relationship between use of sildenafil (Viagra) and melanoma.  That study had only 142 cases of melanoma, and of these men 14 had used sildenafil.  This study got a lot of publicity leading numerous patients to express concern over whether erectile dysfunction drugs could cause melanoma. Our goal was to look more closely at this issue in a larger population from Sweden (including 4065 melanoma cases of whom 435 used any type of erectile dysfunction drug- Viagra, as well as Levitra and Cialis).  Sweden has a national health system so we were able to access prescription records for men across the entire country, which we linked to the national registries for melanoma and basal cell skin cancer.   (more…)
Author Interviews, Coffee, Erectile Dysfunction, PLoS, University Texas / 26.05.2015

David S. Lopez, Dr.P.H., M.P.H. Assistant professor University of Texas Health School of Public Interview with: David S. Lopez, Dr.P.H., M.P.H. Assistant professor University of Texas Health School of Public Health Medical Research: What is the background for this study? What are the main findings? Dr. Lopez: Coffee, and its most studied component, caffeine, have been implicated in potential health benefits due to the rich sources of antioxidants and anti-inflammatory compounds contained in this beverage. Caffeine intake reduced the odds of prevalent erectile dysfunction, especially an intake equivalent to approximately 2-3 daily cups of coffee (170-375 mg/day). This reduction was also observed among overweight/obese and hypertensive men, but not among diabetic men. These associations are warranted to be investigated in prospective studies. Medical Research: What are the main findings? Dr. Lopez: Caffeine intake reduced the odds of prevalent erectile dysfunction, especially an intake equivalent to approximately 2-3 daily cups of coffee (170-375 mg/day). This reduction was also observed among overweight/obese and hypertensive men, but not among diabetic men. These associations are warranted to be investigated in prospective studies. (more…)
Author Interviews, Baylor College of Medicine Houston, Cost of Health Care, Erectile Dysfunction, Heart Disease / 03.03.2015

Alexander W. Pastuszak, MD, PhD Male Reproductive Medicine and Surgery Scott Department of Urology Baylor College of Medicine Houston, TX Interview with: Alexander W. Pastuszak, MD, PhD Male Reproductive Medicine and Surgery Scott Department of Urology Baylor College of Medicine Houston, TX   Medical Research: What is the background for this study? Dr. Pastuszak: The link between erectile dysfunction (ED) and cardiovascular disease (CVD) has been growing stronger in recent years, and recommendations have recently been made to screen men with ED for CVD risk factors.  The arteries in the penis are much smaller than those in the heart, and if vascular disease contributes to ED, which we know it does, then ED should be detected before CVD in affected men.  We also know that treating men with CVD risk factors results in improvement in their risk of having acute cardiovascular events (i.e. heart attack, stroke, etc.).  Because of these relationships, we wanted to assess the economic impact of screening men with erectile dysfunction for CVD, identifying men with CVD risk factors, and treating these men on the incidence of cardiovascular events and new cases of ED.  Specifically, we wanted to look at the costs associated with screening and treatment of CVD and erectile dysfunction, and the cost savings resulting from screening and treating men with CVD risk factors and ED when preventing acute cardiovascular events. Medical Research: What are the main findings? Dr. Pastuszak: We modeled the reduction in acute cardiovascular events and the associated cost savings over 20 years.  We predicted that approximately 5.8 million men with both CVD and ED would be identified over 20 years if we screened men with ED for CVD risk factors, and the cost of this screening would be $2.7 billion.  We assumed that if we treated these at-risk men, there would be an approximately 20% decrease in cardiovascular events, which would prevent 1.1 million cardiovascular events over 20 years, saving $21.3 billion that would otherwise be put to treatment of these acute events.  Since ED and CVD arise from the same pathology, we predicted that in treating the CVD risk factors, a similar decrease in ED cases would be seen as well, which would save $9.7 billion that would otherwise be put to ED treatment.  In screening these men, a combined $28.5 billion would be saved over 20 years. (more…)
Author Interviews, Erectile Dysfunction, JAMA, Prostate, Prostate Cancer, Radiation Therapy / 01.04.2014

Dr. Thomas M. Pisansky MD Mayo Clinic, Rochester, Interview with: Dr. Thomas M. Pisansky MD Mayo Clinic, Rochester, Minnesota What are the main findings of the study? Dr. Pisansky: This patient-reported outcomes research did not identify a beneficial effect of once-daily tadalafil to prevent radiotherapy-related erectile dysfunction in men with prostate cancer. (more…)